OAC stands for Open Audio Codec. It is a next-generation royalty-free audio codec being developed by the Alliance for Open Media as the successor to Opus.
Background
OAC development began in early 2026. The codec is based on the Opus source code and aims to surpass it in compression efficiency and quality. At this stage, OAC is still a fork of Opus with renamed symbols and no finalized specification or standardization schedule.
The reason for moving away from Opus to an OAC codec is the umbrella given by the Alliance for Open Media (especially the patents related protections by the alliance).
The Alliance for Open Media - the same consortium behind the AV1 and AV2 video codecs - is developing OAC with backing from Google, Mozilla, Microsoft, Apple, Netflix, Amazon, Meta and others.
OAC and WebRTC
If OAC matures and is standardized, it could eventually replace Opus as an optional or even mandatory audio codec in WebRTC implementations. Together with AV1/AV2 for video, OAC would complete the Alliance for Open Media's royalty-free media stack - no patent licensing costs from organizations like MPEG-LA.
For now, Opus remains the standard audio codec in WebRTC, opterating at bitrates from 6 kbps to 510 kbps with support for narrowband through wideband audio.
